An obesity-fighting strategy launched by the Assembly government in 2005 is failing to deliver, says a highly critical report.
According to the Assembly's audit committee, three-and-a-half years on, none of the "key building blocks" needed to deliver the aims of Climbing Higher for adults and children is in place, including funding. In Wales, 22 per cent of children are obese or overweight and a quarter of young people aged 11-16 are unhealthily inactive.
One of the aims of Climbing Higher is for 90 per cent of all secondary pupils to exercise for one hour, five times a week.
But the report says there needs to be a huge cultural and behavioural change from the Welsh public - as well as better collaboration - for there to be progress.
Its biggest criticism is that the Assembly government is not promoting the scheme well enough to have an impact nationally.
The report was released as the plight of a 33-stone Welsh schoolgirl dominated headlines around the world. Fifteen-year-old Georgia Davis, from Aberdare in Rhondda Cynon Taf, reportedly comfort-eats around 13,000 calories a day. Now she hopes to lose 20 stone while spending six months in an American "fat camp".
Wales is often accused of lagging behind Scotland and England in healthy- eating promotions. In England, almost every child up to the age of 11 has their height and weight recorded as part of a non-compulsory scheme. But recent Assembly government plans to make schools legally responsible for pupils' diets have been met with resistance.
Iwan Guy, acting director of the National Association of Head Teachers Cymru, responding to the proposals for an all-Wales law to control what children can eat at school, said: "Schools serve up only a small proportion of the food children eat every day and they cannot be held accountable for their diet."
But the news is not all bad. Some schemes at local level to boost pupils' activity within schools are proving successful.
Last week, Welsh exam board the WJEC also launched its new A-level PE specification, which places health, wellbeing and exercise at the top of its agenda.
The new course, available from September, focuses on contemporary issues such as lifelong involvement in physical activity.
In the past nine months, 65 schools from 16 local authorities have also successfully applied to the ActiveMarc Cymru PE accreditation scheme, an initiative by the Sports Council for Wales and the Association for Physical Education.
The scheme gives a formal stamp of approval to schools that show a commitment to developing high-quality PE and promoting physical activity. The physical education and school sport scheme (PESS) is a significant part of the initiative and is successful at schools where it is provided for by the local authority.
Philip Carling, chair of the Sports Council for Wales, said: "School sport should not be underestimated - it plays a pivotal role in helping to achieve a healthier Wales."
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CLIMBING HIGHER'S BID TO BEAT OBESITY
All children of primary school age will participate in sport and physical activity for at least 60 minutes, five times a week.
All primary schools will provide a minimum of two hours of curriculum- based sport and physical activity per week.
At least 90 per cent of secondary school pupils will participate in sport and physical activity for 60 minutes, five times a week.
All secondaries will provide a minimum of two hours of curriculum-based and one hour of extra-curricular sport and physical activity per week.
`SHE SHOULD HAVE GONE GOLD IN ATHENS'
The headteacher at the former school of Olympic cycling champion Nicole Cooke paid tribute to her "amazing" achievement this week.
But Chris Davies, head of Brynteg Comprehensive School in Bridgend, said her win in Beijing was not really a shock and that she should have brought the gold medal home from the Athens Games in 2004.
Now he hopes Miss Cooke's success will encourage more of his pupils to take up cycling.
"Despite new cycling sheds at the school, it hasn't really taken off," he said. "Traffic fears are a huge concern of pupils and parents."
Mr Davies was head at the school when Miss Cooke was a pupil. He remembers her as a "complete all-rounder" who could have taken her pick of universities but decided instead to dedicate her life to chasing her Olympic dream.
"As a world-class cyclist she never forgot her school and still pops in on occasions," he said.
"We plan to invite her back in the new term to show off her gold medal to the pupils."
Miss Cooke would cycle to school in all weathers as a pupil alongside her coach - her father, Tony, who was a physics teacher at the school.
Mr Cooke, who now teaches at Cowbridge Comprehensive, watched his daughter triumph in the wet and humid conditions of the Chinese capital from the family home at Wick, in Vale of Glamorgan.
Miss Cooke, 25, became the 200th Briton to win a gold medal at the modern Olympic Games. She is also the first Welsh gold medallist for 36 years.
She raced into the record books after holding off her Swedish and Italian opponents in the last few metres. It was Team GB's first gold of the Games.